1. Field of the Invention
The present invention relates to a pre-whitening filter of a receive end in a multiple antenna system. More particularly, the present invention relates to an apparatus and method for selectively using a Minimum Mean Square Error (MMSE) scheme or a Maximum Ratio Combining (MRC) scheme depending on the existence or absence of inter-cell interference in a receive end of a multiple antenna system.
2. Description of the Related Art
With a rapid growth of the wireless mobile communication market, there is an increase in the demand for diversity of multimedia services in the wireless environment. Accordingly, as a large capacity of transmission data and a high speed of data transmission are implemented to provide multimedia services, extensive research of multiple antenna systems capable of efficiently using limited frequency resources is being conducted.
The multiple antenna system can increase transmission reliability and data rate compared to a single antenna system without additional frequency or transmission power allocation through data transmission using an independent channel.
The typical receiving method used in the multiple antenna system can be an MMSE scheme and an MRC scheme. In the environment in which there is inter-cell interference, an MMSE receive end has more excellent reception performance than an MRC receive end. However, when there is no inter-cell interference, the MMSE receive end exhibits a lesser reception performance than the MRC receive end. For example, when there is no inter-cell interference, the MMSE receive end has poor reception performance because off-diagonal elements do not converge to ‘0’ at the time when the Rnn−1 calculation necessary for MMSE weight calculation is performed.
Thus, a receive end of a multiple antenna system needs a method for selectively using an MMSE scheme or an MRC scheme depending on the existence or absence of inter-cell interference to improve reception performance.